1. Field of the Invention
The present invention relates to a multilayered molding and a method of manufacturing the same, the multilayered molding being structured by a base molding body made of a synthetic resin and a surface layer made of another type of synthetic resin and layered on the base molding body.
2. Discussion of Related Art
Hitherto, multilayered moldings are known that are structured by a base molding body made of a polyolefin resin and a surface layer made of another type of synthetic resin and layered on the base molding body as a 3D-molding whose surface is protected, or decorated by the synthetic surface layer which is printed as needed.
Such multilayered molding can be obtained in such a manner that: a synthetic resin sheet which had been previously molded by being attracted to the inner surface of the cavity of the injection mold by vacuum forming, and a synthetic resin in fluidized and plasticized state is injection-molded in the cavity. They are widely used mainly as interior or exterior parts for automobiles and building materials.
The molded bodies of the type described above has an advantage in that pictures on the molded bodies can be easily achieved simultaneously with the molding work by using the surface layer which had previously been drawn with letters or patterns.
Hitherto, the synthetic resin sheet or film used as the surface layer comprises, for example, polyvinyl chloride. However, the conventional materials for the surface layer suffers from a poor attracting performance at the vacuum forming so that it becomes difficult to form a molding work having a complex 3D shape. As a result, there arises problems that cracks are generated at the corners and that the generation of wrinkles cannot be prevented. Furthermore, the quality of the embossment applied to the inner surface of the mold cavity by transferring the emboss pattern is insufficient. In addition, the surface layer made of polyvinyl chloride suffers from poor heat and low temperature resistance, causing the plasticizer therein to bleed out. As a result, such materials are insufficient to be used as interior parts for automobiles because of their rough touch. In addition, a problem arises in that the damage resistance is insufficient as well.
The inventors of the present invention have disclosed the multilayered moldings in Japanese Patent Laid-Open Nos. 57-20344, 57-188327, 60-87047, and 60-127149. The present invention is disclosed for the purpose of providing a further improved multilayered molding and a method of manufacturing the same.